JP2008111656A - Explosive loading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a loading time of an explosive and to enhance working efficiency, in a blasting work. <P>SOLUTION: In this explosive loading method of the present invention, an explosive loading specific gravity in a blasting hole is changed by regulating a loading speed of an explosive, when loading a water-in-oil type emulsion explosive containing an oxidant, water, an emulsifier, a micro hollow spherical body, and oils (with the provision that all or one part thereof is replaced with a resin), and formed into granular particles, into the blasting hole, using an explosive loading machine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an explosive loading method. More particularly, the present invention relates to a method of loading a water-in-oil emulsion explosive used for industrial blasting operations such as tunnel excavation, quarrying, mining and the like.

As industrial explosives used for blasting work, dynamite, hydrous explosives, ammonium nitrate explosives, nitrate oil explosives (hereinafter referred to as ANFO explosives) and the like are well known. Among these explosives, hydrous explosives are relatively safer than conventional dynamite because they do not contain explosive components with a high degree of danger in the composition, and are widely used as industrial explosives. Since this hydrous explosive has been disclosed as a slurry explosive in Patent Document 1, various improvements have been made, and now it has performance superior to conventional explosives in terms of water resistance and safety. Things have been obtained.

On the other hand, at the blasting site, mechanization of explosive charging work is required from the viewpoint of shortening the loading time of explosives and ensuring safety to avoid the danger from falling rocks near the face during loading work. It is coming. In order to load the explosives mechanically, the explosive used must be safer, and a method of mechanically loading the ANFO explosive with a loading machine or the like has been put into practical use in mines and quarries.

However, the ANFO explosive has a poor residual gas composition after blasting as compared with the water-in-oil emulsion explosive, so that it is necessary to provide a sufficient exhaust device. In addition, when water is present in the blast hole, the ANFO explosive dissolves in water and a predetermined explosive performance cannot be obtained, making it difficult to use. For this reason, in blast holes and spring holes where water exists, a complicated method is adopted in which after the water in the blast hole has been discharged in advance, a polytube or the like is inserted, and then an ANFO explosive is loaded into the polytube. May be. For water-in-oil emulsion explosives, for example, as described in Non-Patent Document 1, in foreign countries, a water-in-oil emulsion explosive called a bulk emulsion explosive is directly blasted using an air-driven monopump or the like. A method called a bulk emulsion explosive system that automatically loads a battery is already in practical use. However, in a bulk emulsion explosive system, since a high-viscosity water-in-oil emulsion explosive is used, the cleaning work after the charge operation and the management of the residual explosive become extremely complicated, which may increase the cost. Moreover, in order to load a bulk emulsion explosive, an expensive loading machine is required to ensure safety.

In addition, various control blasts such as the smooth blasting method are currently being carried out in tunnels and the like in order to prevent excessive digging of the peripheral holes, but these controlled blasts are powerful explosives in the center of the tunnel and powerful in the peripheral holes. Different explosive types are used, such as explosives with reduced pressure, or those with a diameter smaller than the normal one, so the work efficiency when loading explosives is not very good. It is impossible to adjust the power even with machine-loadable ANFO explosives, and it is necessary to use several kinds of explosives when performing control blasting such as smooth blasting, which makes the work very complicated. is the current situation.

For this reason, there is a demand for a highly safe explosive that can be charged with a relatively simple machine such as an air loading machine, can be used even in a blast hole where a relatively large amount of water exists, and is highly safe. As explosives for solving these problems, for example, granular or granular water-in-oil emulsion explosives described in Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5 have been developed, but are still sufficient. It can not be said.

U.S. Pat. No. 3,161,551 JP-A-7-223888 (Claims) Japanese Patent Laid-Open No. 11-278975 (Claims) JP 2001-172096 A (Claims) JP 2001-206797 A (Claims) "Study report on effective tunnel technology" published by Japan Tunnel Technology Association

An object of the present invention is to provide an explosive loading method capable of shortening the loading time of explosives in blasting work, automating the loading work, and improving work efficiency.

As a result of intensive studies to solve such problems, the present inventors have charged a water-in-oil emulsion explosive consisting of specific components molded into granules using an explosive loading machine. By changing the charge speed of the explosive and changing the specific gravity of the explosive loading in the blasting hole to the desired range, the power of the explosive can be adjusted, and while using the same kind of explosive, for example, smoothing the peripheral hole in tunnel excavation The present invention has been completed by finding that blasting is possible.

That is, the present invention
(1) Explosive loading with water-in-oil type emulsion explosive containing granular material and containing oxidant, water, emulsifier, micro hollow sphere and oil (however, all or part is replaced by resin) Explosive loading method characterized by changing the specific gravity of explosive loading in the blasting hole by adjusting the charge speed of the explosive when loading into the blasting hole using a machine (2) Explosive loading machine is pressure In addition to the compressed air from the container, the charge hose, the pneumatic feeder, and the pressure vessel, the air loader is composed of a device for sending the compressed air to the charge hose. The charging method according to the above (1), wherein the compressed air sent into the charging hose separately from the pressure vessel is adjusted to 0.05 to 0.7 MPa, and the explosive is loaded ( 3) The average weight per grain of explosives is 0. 3~5.0g der above (1) or (2) The method of loading, wherein

The explosive loading method of the present invention can shorten the charging time and improve the work efficiency when charging a water-in-oil type emulsion explosive using an explosive loading machine, and various methods such as a smooth blasting method can be used. Blast patterns can be implemented with a single explosive.

The present invention will be described in detail below.
The explosive loading machine used in the present invention may have any form as long as it is composed of a container for storing explosives, a charge hose, and an explosive supply device. For example, a preferable example is an air loader configured of a pressure vessel for charging an explosive, such as an ANFO loader, a charge hose, and a pneumatic feeder.

The air loading machine is preferably provided with a device for sending compressed air to the charging hose separately from the compressed air from the pressure vessel in the vicinity of the connection between the pressure vessel and the charging hose. For example, a double pipe is used for the connection part of a pressure vessel and a charge hose, and what has a structure which sends an explosive from a pressure vessel inside a double pipe, and compressed air to the outside simultaneously is mentioned. In the transport of explosives only with compressed air from the pressure vessel, there may be a problem that the explosives are blocked in the charge hose. However, by sending only compressed air into the charge hose separately from the pressure vessel, it is possible to transport the explosive by reducing the occupation ratio of the explosive in the charge hose, which can solve the problem of explosive blockage .

A charge hose having an inner diameter of 15 to 40 mm is used. The charging hose may be connected with a different outer diameter depending on the diameter of the blast hole, but it is preferable to reduce the outer diameter only at the tip of the charging hose in order to prevent clogging during charging.

In the present invention, by changing the charge speed and adjusting the impact force that causes the water-in-oil emulsion explosive (hereinafter sometimes referred to simply as a granular explosive) formed into a granular shape to collide with the blast hole wall, The explosive is deformed to change the packing density, that is, the charge specific gravity, to a desired level. Although there is no restriction | limiting in particular in the method of a charging speed, When using the air loading machine which is a preferable embodiment of this invention, what is necessary is just to adjust a loading pressure moderately. In this case, in order to avoid the problem of the explosive clogging in the charging hose as described above, a device having a device for sending compressed air to the charging hose is preferably used separately from the compressed air from the pressure vessel. To do.

The charge rate in the present invention refers to the amount of explosive supplied per minute, and it is usually preferable to change the charge rate within a range of about 10 to 40 kg / min. In order to adjust the explosive supply speed within this range, for example, when the preferred loading machine in the present invention is used, the pressure in the pressure vessel is 0.1 to 0.5 MPa, preferably 0.2 to 0.4 MPa, Moreover, the compressed air sent into the charging hose separately from the pressure vessel is set to 0.05 to 0.7 MPa, preferably 0.2 to 0.5 MPa.

The granular explosive used in the present invention is a water-in-oil emulsion explosive in which all or part of explosive oils containing an oxidizing agent, water, an emulsifier, a fine hollow sphere, and oils are replaced with a resin. Use things.

Hereinafter, the granular explosive used in the present invention will be described.
The granular explosive oxidizer is preferably used as an aqueous solution. Specific examples of oxidants that can be used include alkali metal nitrates such as ammonium nitrate and sodium nitrate, alkaline earth metal nitrates such as calcium nitrate, and chlorine. Alkali metal chlorates such as sodium phosphate, alkaline earth metal chlorates such as calcium chlorate, alkali metal perchlorates such as potassium perchlorate, alkaline earth metals such as calcium perchlorate Examples include perchlorates and ammonium perchlorate, and these can be used alone or in combination. Particularly preferred among these oxidants are ammonium nitrate and sodium nitrate.

Oxidant aqueous solutions of granular explosives include water-soluble amine nitrates such as monomethylamine nitrate, monoethylamine nitrate, hydrazine nitrate, dimethylamine dinitrate, water-soluble alkanolamine nitrates such as methanolamine nitrate, ethanolamine nitrate and the like. Water-soluble ethylene glycol mononitrate or the like can be added as an auxiliary sharpening agent.

The content of water in the aqueous oxidizing agent solution of the granular explosive is preferably used in such an amount that the crystal precipitation temperature of the oxidizing agent aqueous solution is 30 to 90 ° C., and is usually 5 to 40 wt. %, Preferably in the range of 7 to 30% by weight.
In the oxidizing agent aqueous solution, a water-soluble organic solvent such as methyl alcohol, ethyl alcohol, formamide, ethylene glycol or glycerin can be used as an auxiliary solvent in order to lower the crystal precipitation temperature. The oxidizing agent aqueous solution is contained in the explosive in the range of 50 to 95% by weight.

As an emulsifier for a granular explosive, an emulsifier usually used in a water-in-oil emulsion explosive, such as an alkali metal stearate, ammonium stearate, calcium stearate, polyoxyethylene ether salt, sorbitan fatty acid ester, sorbitol fatty acid ester These are used as one kind or a mixture of two or more kinds. The emulsifier is contained in the explosive in the range of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.

Specific examples of oils contained in granular explosives include petroleum oils such as light oil, kerosene, mineral oil, lubricating oil and heavy oil, petroleum waxes such as paraffin wax and microcrystalline wax, and other hydrophobic vegetable oils. , Vegetable waxes, animal oils, and animal waxes, which can be used alone or in combination of two or more. Oils are contained in the explosive in the range of 0.1 to 20% by weight, preferably 1 to 10% by weight.

The granular explosive in the present invention is used by replacing part or all of the oils with a resin that is oil-soluble or compatible with oils. The resin used may be a resin that can be injection-molded with a water-in-oil emulsion explosive and does not react with the emulsion base material in order to maintain the stability of the water-in-oil emulsion. Preferred are thermosetting resins that are liquid or low melting at room temperature, thermoplastic resins that are fluid when heated at room temperature, and synthetic rubbers. Specific examples include phenol resins, petroleum resins, polyethylene, and ethylene vinyl acetate copolymers. , Polybutadiene, styrene butadiene rubber and the like. In addition, since a molten resin is used in the production of explosives, the melt flow rate measured based on the “thermoplastic flow test method” described in JIS K7210 is 10 g / 10 min. Or more, preferably 15 g / 10 min. It is preferable to use the above. These resins can be mixed and used as part of oils contained in a mixture (water-in-oil emulsion base material) composed of an oxidant, oil, and emulsifier, or as a water-in-oil emulsion explosive. It can also be mixed as an additive.

The granular explosive can provide a wide range of sensitivity performance from detonator initiation to booster initiation by including an appropriate amount of hollow microspheres. As the fine hollow spheres, for example, inorganic hollow spheres such as glass microballoons and shirasu balloons, or organic hollow spheres such as foamed styrene and resin balloons, or a mixture of two or more kinds thereof are used. The amount of the fine hollow sphere varies in a wide range according to the use of the explosive, and it cannot be generally described because it depends on the specific gravity of the fine hollow sphere, but usually the specific gravity of the explosive is 1.4 g / cc or less, The amount is preferably 1.3 g / cc or less.

It is possible to add metal powder such as aluminum powder and magnesium powder, and organic powder such as wood powder and starch to the granular explosive.
The shape of the granular explosive is not particularly limited, and may be any of a spherical shape, a cylindrical shape, a disk shape, a prismatic shape, and the like, and is formed into an arbitrary shape by a molding machine used for molding. For example, a method of forming a column with a commonly used extrusion molding machine, a method of spheroidizing with a granulator, or the like can be used. As the size of the molded product, it is desirable that the average weight per one explosive molded product is 0.03 to 5 g. The size of the explosive cannot be generally specified depending on its shape, but in the case of a cylindrical shape, a diameter of about 3 to 10 mm and a length of about 5 to 15 mm are preferable.

In the granular explosive, an anti-adhesive agent can be attached to the surface as necessary after molding. As the adhesion preventing agent, a powder having an average particle size of 500 μm or less, preferably an average particle size of 300 μm or less is used. Specific examples of usable powders include metal salts such as calcium carbonate and magnesium carbonate, metal oxides such as silicon oxide and alumina, minerals such as talc, kaolin and bentonite, fatty acid amides, resin hollow spheres, etc. Organic powder, glass powder, etc. are mentioned. If the amount of the anti-adhesion agent used is too small, the prevention effect is not sufficient, and if it is too large, the explosive performance may be reduced. Since it varies depending on the specific gravity of the powder to be used, it cannot be generally stated, but it is usually attached to the granular explosive in an amount of about 0.03 to 5% by weight.

A granular explosive is manufactured as follows, for example. The oxidizing agent and, if necessary, the auxiliary sharpening agent are dissolved in water at about 85 to 95 ° C. to obtain an aqueous oxidizing agent solution. Next, the aforementioned aqueous oxidizer solution is gradually added to a mixture of oils and emulsifier heated to about 85 to 95 ° C. with sufficient stirring. The resulting water-in-oil emulsion is added with hollow microspheres, if necessary, other additives, resin that is oil-soluble or compatible with oils, and mixed with a kneader to produce a water-in-oil emulsion explosive. Get. After this water-in-oil type emulsion explosive is molded by an extrusion molding machine or the like, powder is mixed as an anti-adhesion agent as necessary to obtain a granular explosive. Resins exhibiting oil solubility or compatibility with oils can be mixed in a step of mixing oils or in a micro hollow sphere. Since the obtained granular explosive has a granular shape, it can be easily loaded into the blast hole using an explosive loading machine. In addition, since it has high water resistance and a specific gravity greater than 1, it can be used without any trouble even when it is loaded into a vertical hole.

In the present invention, the granular explosive has a characteristic that it is difficult to agglomerate under static pressure even when it is subjected to its own weight during storage or transportation, or in a charge tank such as an explosive loading machine, and has a plasticity that easily deforms under dynamic pressure. Use what you have. For example, a material that is easily deformed to the extent that a 10 g weight is dropped from the position of 10 cm above the explosive is preferable. Because of this plasticity, unlike the ANFO explosive that exhibits the same granular form, it is possible to easily change the loading specific gravity within the blast hole.

The granular explosive used in the present invention is formed into a granular shape and has the above-mentioned characteristics, but when the specific gravity is small, for example, 0.5 to 0.75 g / cc, the detonation speed is 2500 to 3500 m / s, When the loading specific gravity is large, for example, 0.75 to 0.95 g / cc, it is preferable to use one whose detonation speed changes from 3500 to 4500 m / s.

In the loading method of the present invention, the explosive loading specific gravity can be adjusted in the range of 0.6 to 1.10 g / cc. In addition, in order to load with the explosive loading specific gravity desired at the blasting site, it is only necessary to charge the steel pipe having the same size as the blasting hole at a different speed and calibrate the loading specific gravity with respect to the charging speed.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
A 90 ° C. aqueous oxidizing agent solution comprising 74.3 parts by weight of ammonium nitrate, 4.8 parts by weight of sodium nitrate, and 10.5 parts by weight of water, 1.9 parts by weight of microcrystalline wax, 0.8 parts by weight of ethylene vinyl acetate copolymer, In addition to 2.9 parts by weight of sorbitan monooleate, the mixture was sufficiently stirred and mixed to obtain a water-in-oil emulsion. To this, 3.8 parts by weight of glass microballoon as fine hollow particles was added and mixed by stirring to obtain a water-in-oil emulsion explosive. This water-in-oil emulsion explosive is molded by an extrusion molding machine with a 5 mm diameter die, cut with a knife so that the length is 8 mm, and then mixed with 1.0 part by weight of talc to obtain a granular explosive. It was. This granular explosive is supplied to an ANFO loading machine (KY-1; manufactured by Kayatech Co., Ltd.) equipped with a pressure vessel and a charge hose (inner diameter: 32 mm, length: 30 m) for supplying compressed air separately from the pressure vessel. A steel pipe with an inner diameter of 48 mm, a length of 1 m, and a wall thickness of 5 mm, using a loading machine equipped with the apparatus, setting the pressure in the pressure vessel to 0.5 MPa, and the pressure of compressed air sent separately from the pressure vessel to 0.3 MPa. The charge was confirmed and the detonation rate was measured by the Dortrish method.

Example 2
Using the same granular explosive as in Example 1, the same air loading machine as in Example 1 (the pressure inside the pressure vessel is 0.3 MPa, the pressure of the compressed air sent separately from the pressure vessel is 0.3 MPa, the charging hose Was loaded into a steel pipe with an inner diameter of 48 mm, a length of 1 m, and a wall thickness of 5 mm, and the state of the charging was confirmed and the detonation speed was measured by the Dortrish method. .

Example 3
Using the same granular explosive as in Example 1, the same air loading machine as in Example 1 (the pressure in the pressure vessel is 0.2 MPa, the pressure of the compressed air sent separately from the pressure vessel is 0.2 MPa, the charging hose Was loaded into a steel pipe with an inner diameter of 48 mm, a length of 1 m, and a wall thickness of 5 mm, and the state of the charging was confirmed and the detonation speed was measured by the Dortrish method. .

Example 4
The same granular explosive as in Example 1 is put in the pressure vessel of the same air loading machine as in Example 1, and after applying a load of 0.7 MPa in the vessel, the pressure in the pressure vessel is 0.3 MPa, separately from the pressure vessel The pressure of the compressed air to be sent was set to 0.3 MPa, and it was confirmed whether normal charging could be performed using a charging hose having an inner diameter of 32 mm and a length of 30 m.

Table 1 shows the loading specific gravity, charge speed, and detonation speed of Examples 1 to 4.

Claims (3)

Using an explosive loading machine, a water-in-oil emulsion explosive that contains an oxidizing agent, water, an emulsifier, micro hollow spheres, and oils (however, all or part of them are replaced with resin) and is molded into granules An explosive loading method characterized by changing the specific gravity of the explosive loading in the blast hole by adjusting the charging speed of the explosive when loading into the blast hole. The explosive loading machine is an air loading machine composed of a device for sending compressed air to the charge hose separately from the pressure vessel, charge hose, pneumatic feeder and compressed air from the pressure vessel, The pressure in the container is adjusted to 0.1 to 0.5 MPa, and the compressed air sent into the charge hose separately from the pressure container is adjusted to 0.05 to 0.7 MPa, respectively, and the explosive is loaded. The loading method described. The loading method according to claim 1 or 2, wherein an average weight per one explosive molded body is 0.03 to 5.0 g.